Lever-cam operated slidable jaw wrench



May 25, 1965 w. K. BERGMAN 3,185,000

LEVER-CAM OPERATED SLIDABLE JAW WRENCH Filed May 14, 1965 INVENTOR.

WAyNe K. 55:1; MAN

TORNEY United States Patent 3,185,000 LEVER-CAM OPERATED SLKDABLE .IAW WRENCH Wayne K. Bergman, 927 Butler St., Toledo 5, Ohio Filed May 14, 1963, Ser. No. 280,197 3 Claims. (Cl. 81-128) This invention relates to valve wheel wrenches or spanners, and more particularly to an important improvement in lever-cam operated, slidable jaw wrenches of the class described and disclosed in my Patent Number 3,026,751.

In principle the device of the present invention consists essentially of a lever or handle terminating in a dual or bifurcated end portion consisting of upper and lower arms which in turn is pivotally connected to two aligned gripping jaws by means of an adjustable threaded bolt that adjusts the vertical position of the lower gripping jaw. In the invention of my Patent Number 3,026,751, the upper gripping jaw as well as the upper arm of the bifurcated end portion were provided with matching or mating cam surfaces aligned so that when lateral pivotal force is exerted on the lever in either direction, the cam surfaces unmate, and the result is a forcing of the upper jaw toward the lower jaw; thus resulting in the jaws firmly gripping the valve wheel handle or the like between them. Any further lateral force on the lever will result in the rotation of the hand wheel towards either its open or closed position. Having one of the cam surfaces directly on one of the gripping jaws resulted in a wrench that was hard to produce and subject to annoying locking action on the part of the jaw with the cam on it.

In my present invention, hereinafter disclosed, the cam surfaces are removed from the gripping jaws and instead become the upper or top surface of the upper arm of the bifurcated end portion, with a matching or mating cam surface of a separate removable cam piece or portion above it. With reference to Patent Number 3,026,751, the changing of the location of the cam surfaces in the present invention and the fact that the inner surfaces of the upper and lower arms of the bifurcated end portion as well as the top and bottom surfaces of the rear end portion of the upper gripping jaw are in the present invention all substantially flat surfaces, makes for several important improvements over the wrench of my Patent Number 3,026,751.

With the present invention the wrench, and particularly the cam surfaces, can be much more easily manufactured. Also the flat surfaces of the inner surfaces of the bifurcated end portion in contact with the flat surface of the rear portion of the upper gripping jaw makes for smoother and more positive operation of the wrench and particularly prevents locking of the jaws due to tilting or cocking which could result from the cam action being directly on the jaws, as in the wrench of Patent Number 3,026,751.

In the previous wrench, the inside cam surfaces were difficult and costly to manufacture. In the present invention the cam surfaces, due to their outside availability, can be drop-forged or machined much more easily and much more readily repaired or replaced, which reflects itself in a considerably cheaper construction cost. The rise and fall of the cam surfaces of the present invention can be more readily changed to conform to the requirements for quick or slower acting, gripping requirements. The fact that the cam of the present wrench is not on the upper jaw will permit the movement of the cams without the undesirable tendency to lock the upper jaw when under pressure due to the tilting action of the cam action when the cam surface is directly on and a part of the upper jaw.

The flat surfaces of the rear end portion of the upper jaw being snugly received by the flat surfaces of the inner surfaces of the bifurcated end portion or arms, permits rotation of the wrench lever or handle in either lateral direction without imparting a tilting action on the upper lever jaw, which tilting action previously tended to lock it against the bolt. The bolt must remain free to move vertically, up or down, and cannot be locked in any permanent position by the locking action of a cocked jaw. Thus, all the rotation surfaces of the present wrench are fiat and smooth which is easier to produce and more certain of flawless operation.

The fact that the compression ring of the previous wrench of my Patent Number 3,026,751 which urged the upper jaw upwardly and thus forced the cam surfaces together, is no longer needed and is an improvement and permits more stable jaw action. In its place is the lower arm of the bifurcated end portion which carries the weight of the upper jaw in place of the old compression spring. This gives more bearing surface and prevents tilting or cocking of the upper jaw which formerly caused it to lock against the alignment bolt.

Other important objectives are incorporated in the present invention which will hereinafter be described; however, what has already been stated should clearly emphasize that the improvements mentioned are important and substantial improvements in lever-cam operated, slidable jaw wrench, which wrench is a vast step forward in the field of valve wheel wrenches or spanners.

Referring now to the accompanying drawings, forming a part of this specification:

FIGURE 1 is an elevation view of the wrench and handie with the gripping jaws in the open position,

FIGURE 2 is an elevation view of the wrench with the gripping jaws in the closed position,

FIGURES 3A and 3B show two cross-sectional views of the wrench handle or lever at locations shown in FIGURE 1,

FIGURE 4 shows a bottom view of the upper cam piece surface, and

' FIGURE 5 is a cross-sectional view of the upper cam piece shown in FIGURE 4, and

FIGURE 6 is a plan view of the upper jaw.

Now again referring to the accompanying drawings we find that the wrench consists of an elongated handle or lever portion 10 which terminates in a bifurcated end portion 11 which has two arms: upper arm 12 and lower arm 13.

The upper gripping jaw 14 and the lower gripping jaw 15 are pivotally connected to the bifurcated end portion 11 by means of a threaded adjustment bolt 16 which is integral with and forms a vertical, elongated extension from said lower gripping jaw 15. The bolt extends upwardly through circular apertures in each of the upper and lower arms 12 and 13 to permit bolt 16 to rotate and slide vertically within these apertures. The bolt 16 must be designed to keep the upper and lower gripping jaws 14 and 15 in permanent alignment which is accomplished in the present invention by preventing the upper jaw 14 and cam piece 22 from rotating on the bolt 16. This is accomplished in the present invention by providing the bolt 16 with a vertical groove or keyway 13 which in turn receives a matched protrusion or key of the upper gripping jaw 19. A non-circular bolt with a matching aperture in the .upper gripping jaw 14 and ring cam piece 22 could accomplish the same purpose. The bolt 16 is provided with threads '20 at least on its upper end portion so that an adjusting and holding nut 21 can be screwed on to hold the assembly together.

The top or upper surface of the upper arm 12 is formed into a ring cam 12-C, which is designed to cooperate with the removable cam portion 22 having its underside forming a mating cam surfaces 22-0.

The removable cam portion 22 is provided'with an aperture for fitting over the bolt 16, and is provided with a key 23 for fitting into bolt keyway 18 so that the bolt 16 cannot rotate within the removable ring cam piece 22 and so that the removable ring cam piece 22 will also be in permanent alignment with the upper and lower jaws 14 and In more detail, the matching cam surfaces 12-0 and ZZZ-C are designed so that the hills of one match the valleys of the other. The preferred construction of the cam surface 12-C and 22-0 consist essentially of a circular periphery if viewed directly from above or below with central apertures for receiving bolt 16. The working or matching cam surfaces are matched at all points. The surface of the cams are preferably divided into equal quadrants with the high po-ints or hills of one cam matching the low points or valleys of the other cam when. both cams are in their matching or mating position and the jaws are not gripping; On each cam surface there are preferably high points which. are preferably opposite on the circumference as are the low points on each cam surface. The slope of the incline of the cam surfaces W111 The upper gripping jaw 14 has a rear end portion ld-A' provided with smooth, flat upper and lower surfaces 14-B and C. This rear end portion14-A fits snugly within the space between the upper and lower arms 12 and 13, which upper and lower arms inner surfaces. are made smooth and flat so that the rear end portion 14-A of the gripping jaw 14 not only can move or turn easily and smoothly,

but also the twoarms '12. and 13 will hold the gripping jaw 14 and prevent it from tilting when in gripping action. A single compression spring 24 is disposed around the bolt 16 and between the lower gripping jaw 15 and the lower arm 13 to urge the lower jaw 15 away from the' upper jaw 14. In my invention of Patent Number 3,026,- 751 two compression springs were required and the upper jaw was riding on one such spring, which now has been eliminated in the present invention.

The entire assembly can be easily dismantled and re-assembled as all pieces can be removed once the nut 21 is unscrewed. The extension of the bolt keyway 18 from the top of the bolt down makes possible the removal of all pieces.

In operation, the wrench is prepared for use by unscrewing the nut 21 to a pointwhere the spring 24 forces the jaws 14 and 15 apart sufliciently to permit a valve wheel or the like between them as in FIGURE 1. The. nut is screwed down until both the jaws are in contact with the valve wheel as in FIGURE 1. handle is moved laterally in either direction depending on whether the valve is to be opened or closed. This'lateral At this point the I movement immediately forces'the cam. portions 12 and22.

apart as in FIGURE 2, which in turn forces the jaws 14k and 15 together tightly. The greater the force applied to turn the handle 10, the greater the compression force chance of slippage. Hence, while lateral force is being exerted on the valve wheel to open or close it, at the same time increased gripping force is being exerted on the valve wheel. 1

The gripping action is caused by the fact that the removable cam portion 22 will not rotate around bolt lo. However, the arms 12 and 13. can rotate around bolt lo. Any lateral force exerted by the lover or. handle being moved will tend to unmatch or unmate the upper arm cam surface 12-C and therernovable cam portion surface 22-0 as in FEGURE .2. This unmating causes the high point of one cam to begin to climb out of the valley and up the slope of the hill of the other, thus forcing the cams apart. with the result that the bolt is pulled upwardly forcing the lower jaw upwardly toward the upper jaw.

The gripping jaws 14 and 15 are preferably designed to partially encircle the valve wheel wrench and provided with teeth 25 to help prevent slippage.

The preferred cross section of the handle or lever portion 19 as shown in FIGURES 3, is so designed to give maximum strength to the wrench with minimum of metal requirement thus making for .greaterstrength, easier construction and less weight. 7

What has been described is an important improvement over the existing art. Whatis now claimed is:

1. In a device of the class described, a lever handle, a bifurcated end portion on one end portion of and integral with said lever handle, said bifurcated end portion comprising an upper arm and a lower arm extending from said lever handle, a cam surfaceon the uppersurface of said upper arm and substantially flat surfaces on the underside of said upper arm and the upper surface of said lower arm; an upper gripping jaw, a rear portion on said gripping jaw having substantially fiat upper and under surfaces, and saidrear portion fitting snugly within and between said upper and lower arms of said bifurcated end portion; a protruding forward gripping portion on said upper gripping jaw; a lower gripping jaw corresponding to said upper jaw forward gripping portion, a non-circular bolt with an upper threaded portion, and said bolt being integral with and extending verticallyfrom the rear portion of said lower jaw andsaid bolt extending through circular apertures provided in the centerof said upper and lower arms and a non-circular apertureprovided in the center of said rear portion of said upper jaw, said circular apertures being such as to snugly permit rotation of said bolt within it, and said non-circular aperture being'such as to fit snugly around said non-circular bolt and permitting vertical movement but no rotation movement around said bolt, so that said upper and lower jaws move laterally in alignment with each other; a removable cam portion for mating with said cam surface on said upper arm of said bifurcated end portion, said removable cam portion being provided with a non-circular aperture also to snugly fit aroundsaid bolt and to remain in permanent alignment with said upper and lower jaws; a threaded nut for screwing on said upper threaded bolt portion and adjusting position of lower jaw; a compression spring surrounding 1 said bolt and positioned between said lower jaw and said lowerarm of said bifurcated end portion to urge said upper and lower gripping jaws apart.

2. The same as claim 1 with said bolt being circular but having a recessed groove or key Way to receive a protrusion or key from said removable cam portion and'said upper jaw, thus to 'keep 'said removable cam position and said upper jaw and said lower jaw in constant alignment.

3. In a wrench of the class described, a lever, a bifurcated end portionon. said lever, said bifurcated end portion comprising'upper and lower arms extending from said lever, a cam portion on theupper surface of said upper arm, a removable cam' portion disposed above said upperarm and said removable cam portion having a cam surfacefor mating with said upper arm camsurface, a pair of gripping jaws pivotally attached to saidbifurcated end portion so that when said leveris laterally pivoted in either direction the force imparted to said gripping jaws is perpendicular to the plane of movement of said lever causing the cam portions to force said gripping jaws together when said cam portions are forced beyond their mating position by the lateral movement of said lever in either direction, and the under surface of said upper arm and the upper surface of said lower arm being substantially fiat, to recieve the rear end portion of said upper gripping jaw which rear end portion also has a substantially flat upper and lower bearing surface.

References Cited by the Examiner UNETED STATES PATENTS Jacoby 81-115 Smith 81126 Nelson 81165 X Ryland 81165 X Bergman 81129 10 WILLIAM FELDMAN, Primary Examiner. 

1. IN A DEVICE OF THE CLASS DESCRIBED, A LEVER HANDLE, A BIFURCATED END PORTION ON ONE END PORTION OF THE INTEGRAL WITH SAID LEVER HANDLE, SAID BIFURCATED END PORTION COMPRISING AN UPPER ARM AND A LOWER ARM EXTENDING FROM SAID LEVER HANDLE, A CAM SURFACE ON THE UPPER SURFACE OF SAID UPPER ARM AND SUBSTANTIALLY FLAT SURFACES ON THE UNDERSIDE OF SAID UPPER ARM AND THE UPPER SURFACE OF SAID LOWER ARM; AN UPPER GRIPPING JAW, A REAR PORTION ON SAID GRIPPING JAW HAVING SUBSTANTIALLY FLAT UPPER AND UNDER SURFACES, AND SAID REAR PORTION FITTING SNUGLY WITHIN AND BETWEEN SAID UPPER AND LOWER ARMS OF SAID BIFURCATED END PORTION; A PROTRUDING FORWARD GRIPPING PORTION ON SAID UPPER GRIPPING JAW; A LOWER GRIPPING JAW CORRESPONDING TO SAID UPPER JAW FORWARD GRIPPING PORTION, AND SAID BOLT BEING BOLT WITH AN UPPER THREADED PORTION, AND SAID BOLT BEING INTEGRAL WITH AND EXTENDING VERTICALLY FROM THE REAR PORTION OF SAID LOWER JAW AND SAID BOLT EXTENDING THROUGH CIRCULAR APERTURES PROVIDED IN THE CENTER OF SAID UPPER AND LOWER ARMS AND A NON-CIRCULAR APERTURE PROVIDED IN THE CENTER OF SAID REAR PORTION OF SAID UPPER JAW, SAID CIRCULAR APERTURES BEING SUCH AS TO SNUGLY PERMIT ROTATION OF SAID BOLT WITHIN IT, AND SAID NON-CIRCULAR APERTURE BEING SUCH AS TO FIT SNUGLY AROUND SAID NON-CIRCULAR BOLT AND PERMITTING VERTICAL MOVEMENT BUT NO ROTATION MOVEMENT AROUND SAID BOLT, SO THAT SAID UPPER AND LOWER JAWS MOVE LATERALLY IN ALIGNMENT WITH EACH OTHER; A REMOVABLE CAM PORTION FOR MATING WITH SAID CAM SURFACE ON SAID UPPER ARM OF SAID BIFURCATED END PORTION, SAID REMOVABLE CAM PORTION BEING PROVIDED WITH A NON-CIRCULAR APERTURE ALSO TO SNUGLY FIT AROUND SAID BOLT AND TO REMAIN IN PERMANENT ALIGNMENT WITH SAID UPPER AND LOWER JAWS; A THREADED NUT FOR SCREWING ON SAID UPPER THREADED BOLT PORTION AND ADJUSTING POSITION OF LOWER JAW; A COMPRESSION SPRING SURROUNDING SAID BOLT AND POSITIONED BETWEEN SAID LOWER JAW AND SAID LOWER ARM OF SAID BIFURCATED END PORTION TO URGE SAID UPPER AND LOWER GRIPPING JAWS APART. 